(a) Field of the Invention
The present invention relates to an inspecting apparatus for a solar cell of a thin film type and an inspecting method using the same.
(b) Description of the Related Art
A solar cell is a photovoltaic device for converting light energy into electrical energy. Generally, a solar cell of a thin film type has a structure that includes a plurality of cells coupled in series to a plane surface. During manufacturing, areas between the unit cells are inspected for pattern defects and each of the cells is inspected for normal operation.
In a solar cell of the thin film type, a plurality of cells are coupled in series to a plane surface, and the interval between the cells is adjusted according to the particular design method that is used and the structure of the solar cell. The structure can be generally divided into tandem cells and single cells. In the case of a tandem cell, the voltage generated by each cell is high. Hence, when using tandem cells, increasing the area of the unit cell results in an overall increase of the energy that is generated. In the case of a single cell, in which the generated voltage is low relative to the current generated in each unit cell, it may be preferable to decrease the area of each unit cell and increase the number of cells. Also, the amount of generated current is large and the voltage is low in the case of a compound solar cell using CuInGaSe2 as a material, compared with an amorphous solar cell.
Accordingly, by designing a solar cell with a compound material as opposed to amorphous silicon allows the solar cell to be designed with narrower spacing between neighboring unit cells to minimize the area of the unit cell and a higher number of cells. That is, if each solar cell is formed with the most suitable structure, the size of the cell could be different for every solar cell.
This variation in the unit cell size and arrangement poses a challenge during the inspection process, during which a plurality of probe units simultaneously contact the plurality of cells for inspection through electrical switching to test or repair them by effectively probing the plurality of cells. Particularly, a multi-probing unit would need a function for changing the interval between each probe unit according to the different characteristics or the different structures of the solar cells.
However, the capability to simultaneously and uniformly reduce the interval of the individual probe unit is limited by an alignment margin of the individual probe units or the number of multi-probe units that will be used.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.